采用EB-PVD技术制备两种多分层热障涂层的研究

摘要

Two kinds of multilayered thermal barrier coatings (TBCs) were designed and successfully prepared by ion beam assisted deposition (IBAD) and low substrate speed method based on electron beam physical vapor deposition (EB-PVD) , respectively. The microstructure and properties of the layered TBCs was studied. The results show that the present layered structure is accompanied by plenty of interfaces paralleled to the coating surface and density modulation change between adjacent layers. The dominant orientation of the multilayered TBCs can change gradually from (100) to (111), but TBCs still exhibit a non-transformable tetragonal (t') structure. Depending on the difference of layered structure and its location, specimen prepared by low substrate speed has better oxidation resistance, while by IBAD has a significantly longer thermal cycling lifetime.%基于电子束物理气相沉积(EB-PVD)技术,设计并分别采用离子束辅助沉积法和低转速法制备了两种具有分层结构的热障涂层(TBCs),对陶瓷层引入层状结构后的组织结构与性能进行了研究.结果表明,层状结构的引入带来大量平行于沉积面的分层界面和相邻分层间的密度调制变化.层状结构TBCs的占优取向由(100)逐渐变化到(111),但仍都形成了不可转变的四方相(t(’))结构.依据分层结构本身的差异和分层界面所处位置的不同,低转速分层试样具有更好的抗氧化性能,但离子辅助分层试样具有明显更长的热循环寿命.